Photosynthesis

1. Photosynthesis Essential Question: How do plants harness the suns energy?

2. What is Photosynthesis? The process of photosynthesis is a chemical reaction that converts light energy into chemical energy. Photo = light Synthesis = to make It is the most important chemical reaction on our planet.

3. Producers or Autotroph • Organisms that carry out photosynthesis are called • producers or autotrophs - producers are the basis of all of Earth’s food chains

4. Photosynthesis – Where does it occur? • occurs in chloroplasts - the energy in the light is absorbed by the chlorophyll and converted to chemical energy

5. What type of organisms make their own food? Discuss question 6 with your partner then answer it. Algae Plants Some Bacteria

6. Structure of a Chloroplast Thylakoidsfound inside the chloroplast contain the pigmentchlorophyll . thylakoids

7. WHY ARE PLANTS GREEN? Different wavelengths of visible light are seen by the human eye as different colors. Gammarays Micro-waves Radio waves X-rays UV Infrared Visible light Wavelength (nm)

8. Why are plants green? Reflected light Transmitted light

9. THE COLOR OF LIGHT SEEN IS THE COLOR NOT ABSORBED • Chloroplasts absorb light energy and convert it to chemical energy Reflected light Light Absorbed light Transmitted light Chloroplast

10. As the chlorophyll in leaves decays in the Fall, the green color fades and is replaced by the oranges and reds of carotenoids

11. Structure of a Chloroplast -Grana- structures inside the chloroplast that are made of stacks of thylakoids. grana thylakoids

12. Structure of a Chloroplast Stroma – the fluid filled space outside of the grana. stroma contains enzymes necessary to convert CO2 into sugar which stores energy . grana stroma thylakoids

13. Light 6 CO2 6 H2O C6H12O6 + 6 O2 + The Balanced Photosynthesis Equation

14. Reactants Products

15. Structure of a Chloroplast Discuss with your partner… Where the chlorophyll is found Discuss with your partner… Where in the chloroplast is light captured Discuss with your partner… What we call stacks of thylakoids grana Discuss with your partner… What is the term used to describe the fluid filled space stroma thylakoids

16. Discuss and answer questions 11-14 with your partner

17. Question of the Day! How are the thylakoids, grana, and stroma related?

18. Before We begin A little History….

19. light energy  6CO2 + 6H2O + + 6O2 C6H12O6 So what does a plant need? • Bring In • 1. light • 2. Reactants • CO2 • H2O • Waste Product • O2 • Makes and uses the product • Sugar (glucose)

20. The Process of Photosynthesis • Two major parts • Light Reactions • Light Independent reactions (Calvin Cycle)

21. Light Reactions - capture energy in sunlight and transfer it to chemical energy - take place in thylakoid membrane of a chloroplast - Chlorophyll is found in the thylakoid disks and they absorbs energy from sunlight

22. Photosynthesis- Light Reactions Light reaction Light is absorbed by chlorophyll in the thylakoid enzymes split H2O and oxygen is released energy from light is stored in ATP & NADPH

23. Discuss question 20 with your partners, then write your answer on your paper.

24. Discuss question 21 with your partners, then write your answer on your paper.

25. Posted around the room is the info needed to answer questions #22-27. Take your paper with you to write down the answers as you find them.

26. 22.In the light reactions, electron transport chains powers ATP production and stores energy in NADPH which is used to power the Calvin cycle. • Two connected photosystems collect photons of light and transfer the energy to chlorophyll electrons • The excited electrons are passed from the primary electron acceptor to the electron transport chains • Their energy ends up in ATP and NADPH

27. 23.Plants produce O2 gas by splitting (breaking) H2O molecule The O2 liberated by photosynthesis is made from the oxygen in water (H+ and e-)

28. 24.ATP - energy is released when a phosphate group is removed - ADP is then produced (can be converted back to ATP) - Function: the chemical energy used for most cell processes

29. 25. NADP+ • NADPH is formed (functions like ATP = energy) when electrons are added to NADP+ • FUNCTION: the major electron carrier during photosynthesis

30. 26. Carrier molecules supply electrons • NADPH is an unstable molecule that stores chemical energy for the cell

31. 27. What is phosphorylation? The addition of a phosphate group to an organic molecule. Phosphorylation is important for many processes in living cells. ATP is formed during cell respiration from ADP by phosphorylation, in the mitochondria of eukaryotic cells and the chloroplasts of plant cells (photosynthetic phosphorylation).

32. Warm up (on the top of page 63)write the questions then your answers • Write the chemical equation for the light reaction. • Which products will be used in the next phase of photosynthesis? (page 226) • Why cant energy be stored as ATP and NADPH? • What is the second phase of photosynthesis? • What is another name for the second phase of photosynthesis?

33. Photosynthesis- Light Reactions 1. Light reaction • Light is absorbed by chlorophyll in the thylakoid - enzymes split H2O and oxygen is released - energy from light is stored in ATP & NADPH

34. Summary of the Light Reaction Reactants Products Light + H20  O2 + ATP + NADPH Occurs in the thylakoid membrane of the chloroplast

36. Photosynthesis- Second Stage Discuss questions 29 with your partner then answer it. • Calvin Cycle • Light –independent Reaction Can occur during the light or the dark

37. Photosynthesis- Calvin Cycle • The Calvin Cycle takes place in the stroma of the chloroplast • Uses CO2 from the atmosphere and energy from the light reactions stored in ATP & NADPH

38. Steps of Photosynthesis The DARK Reactions = Calvin Cycle • CO2 from atmosphere is joined with the energy stored in ATP and NADPH to form glucose • Glucose can be converted into other molecules like cellulose, which is used for structural support in plant cells.

39. Why store energy from the sun as sugar and not ATP? • - ATP is an unstable compound – it doesn’t last a long time. • - sugar (glucose) is stable and can store the energy for a long period of time. • - sugar can be used to build even larger storage molecules (polysaccharides)

40. Chloroplast • A Photosynthesis Road Map Light Stroma NADP Stack of thylakoids ADP + P Light reactions Calvin cycle Sugarusedfor  Cellular respiration  Cellulose  Starch  Other organic compounds

41. The Process of Photosynthesis • Light reaction (depends on light) • Captures sunlight • Breaks down water molecules to produce electrons to form ATP and NADPH • Produces oxygen as a waste product • Calvin Cycle (does not directly depend on light) • Uses ATP, NADPH (from light reaction), and CO2 to make glucose • Glucose is the product in the Calvin cycle

42. It's not that easy bein' green… but it is essential for life on earth!

43. Glue the photosynthesis concept map onto page 64 of your notebook

44. Photosynthesis Includes Light-Dependent Reactions Calvin Cycle Takes Place in Uses Takes place in Use Water & Energy from Sunlight Thylakoid Membranes Stroma ATP Carbon Dioxide NADPH To Produce Of To Produce Chloroplast Oxygen ATP NADPH Glucose (High Energy Sugars)